EP2064395A2

EP2064395A2 - Joist hanger

Info

Publication number: EP2064395A2
Application number: EP07804359A
Authority: EP
Inventors: Paul Clayton
Original assignee: Simpson Strong Tie International Inc
Current assignee: Simpson Strong Tie International Inc
Priority date: 2006-09-21
Filing date: 2007-09-21
Publication date: 2009-06-03
Anticipated expiration: 2027-09-21
Also published as: EP2064395B1; WO2008035098A3; GB0618609D0; WO2008035098A2

Abstract

A stiffened joist hanger for use in the construction industry comprises first and second side flanges, a seat, at least one back flange, at least one top flange and at least one stiffening element folded from a single piece of material; wherein the seat is provided between the first and second side flanges to form a stirrup for receiving and at least partially enclosing an end portion of a joist; a back flange adjoins at least one of the side flanges in a plane approximately perpendicular to planes including the adjoining side flange and the seat; a top flange adjoins the back flange distal to the seat and in a plane approximately parallel to a plane including the seat; the back flange and the top flange adjoin at a junction to form a bracket for abutting an upper surface and a side surface of a support; and a stiffening element adjoins the back flange and the top flange and extends over their junction for resisting bending of the bracket formed by the back flange and the top flange.

Description

JOIST HANGER

The present invention relates to a joist hanger and, in particular, to a stiffened joist hanger formed from a single piece of material.

Within the context of this specification the word "comprises" is taken to mean "includes, among other things". It is not intended to be construed as "consists of only".

There are a number of different forms of floor joist used in construction, the main three types being: i) traditional rectangular solid sawn timber; ii) engineered timber "I" shaped joists comprising a narrow web and rectangular top and bottom flanges; and iii) engineered timber truss joists comprising rectangular timber top and bottom flanges which are spaced apart by a lattice work of metal webs.

Joist hangers are traditionally used to support horizontal floor joists and roof members from masonry walls. However, traditional masonry joist hangers suffer from the problem that they require a number of courses of masonry built above the top flange of the hanger to enable the hanger to achieve an acceptable safe working load.

A traditional joist hanger is shown in Figure 1 wherein the joist hanger 10 comprises a joist bearing slot 20 formed by opposed parallel spaced apart side flanges 30, 40 and a joining bottom flange 50, the side flanges are joined to an angle bracket 60 by weld lines 70. The angle bracket 60 is arranged such that a first face thereof provides a back flange 61, attached to the joist bearing slot, whilst a second face thereof, provides a top flange 62 arranged at a right angle to the back flange 61. In use, the joist hanger 10, is set with the back flange 61 tight against a supporting block wall, when built to a desired level. The top flange 62, is of course at this point resting on a top surface of the supporting block wall. The block wall then needs to be built up above the joist hanger with . .

additional courses and, it is found that a minimum of three courses of solid block masonry is required above the hanger, with mortar fully cured, before a load can be applied to the joist hanger. Having a requirement of building up three extra courses, necessarily means a delay to the point at which joists may be laid, and therefore a delay to the point at which a floor can be installed.

Failure of the traditional hanger can occur when there is inadequate masonry above the hanger which can lead to crushing of the supporting masonry and unbending of the top flange with respect to the back flange resulting in the hanger sliding off the wall.

The SAFETY FAST ™ hanger which is the subject of GB2354267 achieves an increased bending capacity by the use of stiffening elements. Figure 2 shows an example of the disclosed hanger wherein stiffening elements (24) are provided across the top flange/ back flange junction. However, the SAFETY FAST ™ hanger is formed of two parts and it suffers from the problem that the parts must be integrally connected.

A need exists for new equipment for facilitating the erection of a building structure which can be used easily, which reduces the burden required to secure a joist to supporting masonry, which is strong and which facilitates the use of all known joists including joists of "I" shaped section.

It is an aim of preferred embodiments of the present invention to address or reduce at least one of the problems set out above.

Remarkably, an embodiment of a joist hanger which is the subject of this invention, addresses or solves one or more problems of the prior art by inclusion of integral stiffening elements within a joist hanger folded from a single piece. Advantageously, it has been found that this facilitates creation of a strong and stiff joist hanger.

According to a first aspect of the invention, there is provided a stiffened joist hanger comprising first and second side flanges, a seat, at least one back flange, at least one top flange and at least one stiffening element folded from a single piece of material; wherein the seat is provided between the first and second side flanges to form a stirrup for receiving and at least partially enclosing an end portion of a joist; a back flange adjoins at least one of the side flanges in a plane approximately perpendicular to planes including the adjoining side flange and the seat; a top flange adjoins the back flange distal to the seat and in a plane approximately parallel to a plane including the seat; the back flange and the top flange adjoin at a junction to form a bracket for abutting an upper surface and a side surface of a support; and a stiffening element adjoins the back flange and the top flange and extends over their junction for resisting bending of the bracket formed by the back flange and the top flange.

It will be appreciated that the material may be stretched during the folding of the stiffening element(s). In general, the stiffening element is folded from the plane of a flat sheet of material. Thereafter the fold between the back and top flanges is introduced. A skilled person will be aware that there are physical limits depending on the thickness and malleability of the material being used. Alternative methods of forming the joist hanger according to the present invention from a single piece of material are of course possible, as will be readily understood by a skilled person. One such example is forming of the joist hanger in a die, but any suitable method may be beneficially employed.

An embodiment of the invention provides the advantages that it is more economic and efficient to manufacture compared to the known joist hangers. In addition, unlike a welded two part hanger it does not require secondary protective coatings such as hot dip galvanising for durability, because unlike the known products an embodiment of the invention can be produced of steel sheet which is pre-galvanised.

Preferably, at least one of the side flanges defines one or more fixing _ _

apertures for receiving a fixing (eg a nail or screw). Preferably, the fixing apertures are positioned to facilitate fixing to the flange(s) of an T joist. In addition, preferably the fixing apertures are staggered to minimise the risk of splitting wooden flanges of an T joist.

Preferably, the seat defines one or more fixing apertures for receiving a fixing (eg a nail or screw). Preferably, the fixing apertures are positioned to facilitate fixing to the flange(s) of an 'I' joist. In addition, preferably the fixing apertures are staggered to minimise the risk of splitting wooden flanges of an T joist.

Preferably, at least one of the top flanges defines one or more fixing apertures for receiving a fixing (eg a nail or screw). Preferably, the fixing apertures are positioned to facilitate fixing to the flange(s) of an T joist. In addition, preferably the fixing apertures are staggered.

In a preferred embodiment the stiffening elements project upwardly from the top flange away from the seat. Preferably the stiffening elements project upwardly from the top flange by at least 2mm. More preferably, the stiffening elements project upwardly from the top flange up to the full depth of the mortar bed/course between adjacent brick, block or other courses. Indeed, the stiffening elements may project upwardly from the top flange by at least the depth of the mortar bed/course such that the next brick, block or other course touches or rests on the upstanding stiffening elements. In an alternative embodiment the stiffening elements project downwardly from the top flange towards the seat. Again, the height of the stiffening elements may be such that it/they project downwardly from the top flange by at least 2mm, by up to the full depth of the mortar course between adjacent brick, block or other courses or by at least the depth of the mortar course such that the next brick, block or other course touches or rests on the depending stiffening element(s). Preferably the stiffening element(s) lie in a plane substantially parallel with a plane including the side flange(s).

In an embodiment, a stiffening element extends over the junction of a first end of the back flange and a first end of the top flange to a second end of the top flange over the full length of the top flange. In an alternative embodiment, the stiffening element extends over the junction of the back flange and the top flange and over only part of the length of the top flange. In one embodiment, the stiffening element extends over the junction of the back flange and the top flange to a second end of the back flange. In yet a further embodiment, the stiffening element extends over the junction of the back flange and the top flange and over only part of the length of the back flange.

In an embodiment, first and/or second stiffening elements are provided at first and/or second sides of each top flange.

A preferred embodiment of a stiffened joist hanger according to the invention additionally comprises at least one return leg which adjoins the top flange and extends downwardly therefrom towards the seat; the top flange and return leg adjoining at a junction to form a bracket for abutting the upper surface and side surface respectively of a support. Preferably the return leg(s) lie in a plane or planes approximately parallel to a plane including the back flange(s).

In a further preferred embodiment, the stiffening element adjoins the back flange, the top flange and the return leg over their junctions for resisting bending of the bracket formed by the back flange, the top flange and the return leg. In one embodiment, the stiffening element extends over the junction of the top flange and the return leg over the full length of the return leg. In yet a further embodiment, the stiffening element extends over the junction of the top flange and the return leg and over only part of the length of the return leg.

Different embodiments of the present invention may have similar or the same stiffening elements or combinations thereof.

Preferably, the stirrup is sized to receive a standard size of joist within it.

Preferably, an embodiment of a hanger according to the invention can accommodate any of the known forms of joist. .

In use, an embodiment of a joist hanger according to the present invention can be fixed to a support wherein the top flange rests on an upper surface of the support and the back flange abuts a side surface of the support. The stirrup of the joist hanger projects from the support and is capable of receiving and supporting a joist.

In a second aspect the invention provides a method for connecting a joist to a support which comprises the step of fixing a joist hanger according to a first aspect of the invention to the support and fixing the joist to the joist hanger.

The joist hanger is preferably arranged, in use, such that a lower surface of the top flange sits on the supporting structure and loads carried by the joist are largely transmitted to the supporting structure through said lower surface.

The supporting structure is preferably a wall. Preferably the wall comprises a brick, block or other construction comprising a number of courses each separated by a mortar bed/course. Alternatively, the supporting structure may take any suitable form, including a timber, metal or composite form.

Preferably, the back flange is arranged, in use, to sit flush against the supporting structure as a means of locating the joist hanger with respect to an inner/outer face of the supporting structure.

In use, an embodiment of a joist hanger according to the invention can be fixed to a supporting joist wherein the bottom flange abuts a bottom surface of the supporting joist and the back flange abuts a side surface of the supporting joist. The stirrup of the joist hanger projects from the supporting joist and is capable of receiving and supporting a further joist.

The joist hanger may be provided as part of a prefabricated unit of a supporting structure. Alternatively, the joist hanger and the supporting structure may be integrally formed. Another aspect provides a method of hanging joists which comprises the following steps: a. building a wall up to top flange level; b. placing an embodiment of a hanger according to the invention on the wall; c. optionally building further courses of masonry above the top flange and leaving to cure; d. Installing floor joists; e. optionally installing a floor deck; and f. optionally continuing building of the wall.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows an embodiment of a typical known joist hanger (10);

Figure 2 shows an embodiment of a typical known joist hanger (10) including stiffening elements (24) and formed from at least two parts;

Figures 3 to 12 show sections through various embodiments of a hanger (10) according to the present invention showing possible extent and length of stiffening elements (25); and

Figures 13, 14 and 15 show views of joist hangers (10) according to embodiments of the invention having return legs (90). Figures 13 and 14 show embodiments wherein the back flanges (61) are folded outwardly away from the stirrup and Figure 15 shows an embodiment wherein the back flanges (61) are folded inwardly toward the stirrup.

For the purposes of clarity and a concise description features are described herein as part of the same or separate embodiments, however it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

Referring first to Figures 13, 14 and 15, joist hangers (10) in accordance with preferred embodiments of the present invention will now be described.

A stiffened joist hanger (10) according to an embodiment of the invention comprises first and second side flanges (30, 40), a seat (50), two back flanges (61), two top flanges (62) and four stiffening elements (25) folded from a single piece of a metal or composite material.

The seat (50) is provided between the first and second side flanges (30, 40) to form a stirrup for receiving and at least partially enclosing an end portion of a joist. The back flanges (61) adjoin the side flanges (30, 40) in a plane approximately perpendicular to planes including the adjoining side flanges (30, 40) and the seat (50). The top flanges (62) adjoin the back flanges (61) distal to the seat (50) and in a plane approximately parallel to a plane including the seat (50). The back flanges (61) and the top flanges (62) adjoin at junctions to form brackets for abutting an upper surface and a side surface of a support. The stiffening elements (25) adjoin the back flanges (61) and the top flanges (62) and extend over their junctions for resisting bending of the bracket formed by the back flange (61) and the top flange (62).

The hanger (10) is more economic and efficient to manufacture compared to the known joist hangers (10). In addition, unlike a welded two part hanger (10) it does not require secondary protective coatings such as hot dip galvanising for durability, because unlike the known products an embodiment of the invention can be produced of steel sheet which is pre-galvanised.

The side flanges (30, 40) define fixing apertures (45) for receiving a fixing (eg a nail or screw). The fixing apertures are positioned to facilitate fixing to the flange(s) of an T joist. In addition, the fixing apertures are staggered to minimise the risk of splitting wooden flanges of an T joist. The seat (50) defines fixing apertures (35) for receiving a fixing (eg a nail or screw). The fixing apertures (35) are positioned to facilitate fixing to the lower flange of an T joist. In addition, preferably the fixing apertures (35) are staggered to minimise the risk of splitting a wooden T joist. The seat (50) additionally defines a removable slot (36) to allow passage of a restraint strap.

The top flanges (62) may define one or more fixing apertures (35) for receiving a fixing (eg a nail or screw).

Stiffening elements (25) are provided at first and second sides of each top flange. The stiffening elements (25) project upwardly from the top flanges (62) away from the seat (50). Preferably, the stiffening elements (25) extend upwardly from the top flange (62) in a vertical direction by at least 2mm. More preferably, the stiffening elements (25) may extend upwardly in height terms from the top flange (62) up to the full depth of the mortar bed/course between adjacent brick, block or other courses. Indeed, the stiffening elements (25) may project upwardly from the top flange (62) by at least the depth of the mortar bed/course such that the next brick, block or other course touches or rests on the upstanding stiffening elements (25). In an alternative embodiment the stiffening elements (25) project downwardly from the top flanges (62) towards the seat (50). Again, the height of the stiffening elements (25) may be such that it/they project downwardly from the top flange (62) by at least 2mm, by up to the full depth of the mortar course between adjacent brick, block or other courses or by at least the depth of the mortar course such that the next brick, block or other course touches or rests on the depending stiffening element(s) (25). The stiffening elements (25) lie in a plane substantially parallel with a plane including the side flanges (30, 40).

Return legs adjoin the top flanges (62) and extend downwardly therefrom towards the seat (50); the top flanges (62) and return legs adjoining at junctions to form brackets for abutting the upper surface and side surface respectively of a support. The return leg(s) lie in a plane approximately parallel to a plane including the back flange(s). _ _

The stirrup is sized to receive a standard size of joist within it. Embodiments can accommodate any of the known forms of joist.

In the embodiments shown in Figures 13 and 14 the back flanges (61) project outwardly from the side flanges (30, 40). Alternatively, as shown in Figure 15 the back flanges (61) project inwardly from the side flanges (30, 40). In an alternative embodiment, a single back flange (61) adjoins both side flanges (30, 40). In yet another embodiment, the back flange (61) adjoins both side flanges (30, 40) and the seat (50) (50).

It will be appreciated that many different methods are possible for installing the joist hanger (10) into a particular location.

In a first method, opposed end regions of a joist may be inserted into respective stirrups of joist hangers (10) at either end. Then, with the joist and joist hangers (10) already associated with one another, the joist hangers (10) may be placed directly onto supporting brick or block work.

In a second possible method, joist hangers (10) may be provided already positioned within a supporting structure of a building and the end region of a joist may thereafter be offered up to the mouth region and inserted into the stirrup. In other circumstances, it may be possible feed joists and joist hangers (10) through gaps in a partially formed wall, to place them in position and then build up extra brick or block work around. Other methods or partial combinations of the aforementioned methods will occur to a man skilled in the art and are encompassed by the teachings of this invention.

It will be appreciated that there are many different variations of joist hanger (10) which may be envisaged incorporating the teachings of the present invention.

Referring to Figures 3 to 8, possible embodiments comprise a return leg. . _

In embodiments, the stiffening elements (25) adjoin the back flange, the top flange and the return leg over their junctions for resisting bending of the bracket formed by the back flange, the top flange and the return leg (as shown in figures 4,

5, 7 and 8). In alternative embodiments, the stiffening elements (25) adjoin the back flange and part of the top flange, but not the return leg (as shown in figures 3 and 6).

In embodiments, the stiffening elements (25) extend over the junction of the top flange and the return leg over the full length of the return leg (as shown in figures 5 and 8). In alternative embodiments, the stiffening elements (25) extend over the junction of the top flange and the return leg and over only part of the length of the return leg (as shown in figures 4 and 7).

In embodiments, the stiffening elements (25) extend to the lower edge of the back flange as shown in figures 3, 4 and 5. In alternative embodiments the stiffening elements (25) extend over only part of the back flange as shown in figures

6, 7 and 8.

Different embodiments of the invention have similar or the same stiffening elements (25) or combinations thereof.

Referring to figures 9 to 12, further embodiments do not comprise a return leg.

In embodiments, stiffening elements (25) extend over the junction of a first end of the back flange and a first end of the top flange to a second end of the top flange over the full length of the top flange (as shown in figures 9 and 11). In alternative embodiments, the stiffening element extends over the junction of the back flange and the top flange and over only part of the length of the top flange (as shown in figures 10 and 12).

In embodiments, the stiffening elements (25) extend over the junction of the . _

back flange and the top flange to a second end of the back flange (as shown in figures 9 and 10). In yet further embodiments, the stiffening elements (25) extend over the junction of the back flange and the top flange and over only part of the length of the back flange (as shown in figures 11 and 12).

It will also be appreciated that the invention could be used in prefabricated buildings, with the joist hangers (10) already provided as an integral part of a preformed wall.

The reader's attention is directed to all papers and documents which are referred to herein or filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

It will be appreciated that there are many different variations of hanger (10) which may be envisaged incorporating the teachings of the present invention. Wherever brickwork is referred to in this description, the skilled man will realise that such a term is used by way of example only and that other forms of supporting structure may be used in conjunction with the joist hangers.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. In addition, all of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications are covered by the appended claims.

Claims

1. A stiffened joist hanger comprising first and second side flanges, a seat, at least one back flange, at least one top flange and at least one stiffening element folded or formed from a single piece of material; wherein the seat is provided between the first and second side flanges to form a stirrup for receiving and at least partially enclosing an end portion of a joist; a back flange adjoins at least one of the side flanges in a plane approximately perpendicular to planes including the adjoining side flange and the seat; a top flange adjoins the back flange distal to the seat and in a plane approximately parallel to a plane including the seat; the back flange and the top flange adjoin at a junction to form a bracket for abutting an upper surface and a side surface of a support; and a stiffening element adjoins the back flange and the top flange and extends over their junction for resisting bending of the bracket formed by the back flange and the top flange.

2. A joist hanger according to claim 1 wherein the at least one stiffening element is of a height such that it extends or projects at least 2mm from the adjoining top flange and/or back flange.

3. A joist hanger according to claim 1 or claim 2 wherein at least one of the side flanges defines one or more fixing apertures for receiving a fixing.

4. A joist hanger according to any preceding claim wherein the seat defines one or more fixing apertures for receiving a fixing.

5. A joist hanger according to any preceding claim wherein at least one of the top flanges defines one or more fixing apertures for receiving a fixing.

6. A joist hanger according to any preceding claim wherein the stiffening element(s) project upwardly from the top flange away from the seat and/or downwardly from the top flange towards the seat.

7. A joist hanger according to any preceding claim wherein a stiffening element extends over the junction of a first end of the back flange and a first end of the top flange to a second end of the top flange over the full length of the top flange.

8. A joist hanger according to any preceding claim wherein first and/or second stiffening elements are provided at first and/or second sides of each top flange.

9. A joist hanger according to any preceding claim which additionally comprises at least one return leg which adjoins the top flange and extends downwardly therefrom towards the seat to form a bracket.

10. A joist hanger according to claim 9 wherein the stiffening element adjoins the back flange, the top flange and the return leg over their junctions for resisting bending of the bracket formed by the back flange, the top flange and the return leg.

11. A joist hanger according to any preceding claim which has similar or the same stiffening elements or combinations thereof.

12.A joist hanger according to any preceding claim wherein a removable slot is included in the seat to allow passage of a restraint strap.

13. A method for connecting a joist to a support which comprises the step of fixing a joist hanger according to any preceding claim to the support and fixing a joist to the joist hanger.

14. A method according to claim 13 wherein the supporting structure is preferably a wall. _ _

15. A method according to claim 13 or 14 wherein the back flange is arranged, in use, to sit flush against the supporting structure as a means of locating the joist hanger with respect to an inner/outer face of the supporting structure.

16. A method of hanging joists which comprises the following steps: a. building a wall up to top flange level; b. placing an embodiment of a hanger according to the invention on the wall; c. optionally building further courses of masonry above the top flange and leaving to cure; d. Installing floor joists; e. optionally installing a floor deck; and f. optionally continuing building of the wall.

17. A stiffened joist hanger comprising first and second side flanges, a seat, at least one back flange, at least one top flange and at least one stiffening element folded or formed from a single piece of material; wherein the seat is provided between the first and second side flanges to form a stirrup for receiving and at least partially enclosing an end portion of a joist; the at least one back flange adjoins at least one of the side flanges in a plane approximately perpendicular to planes including the adjoining side flange and the seat; the at least one top flange adjoins the back flange distal to the seat and in a plane approximately parallel to a plane including the seat; the at least one back flange and the at least one top flange adjoin at a junction to form a bracket for abutting an upper surface and a side surface of a support; and the at least one stiffening element adjoins the at least one back flange and the at least one top flange and extends over their junction for resisting bending of the bracket formed by the at least one back flange and the top flange, wherein the at least one stiffening element is of a height such that it extends or projects at least 2mm from the adjoining at least one top flange and/or back flange.

18. A stiffened joist hanger comprising first and second side flanges, a seat, at least one back flange, at least one top flange, at least one return leg, and at least one stiffening element folded or formed from a single piece of material; wherein the seat is provided between the first and second side flanges to form a stirrup for receiving and at least partially enclosing an end portion of a joist; the at least one back flange adjoins at least one of the side flanges in a plane approximately perpendicular to planes including the adjoining side flange and the seat; the at least one top flange adjoins the back flange distal to the seat and in a plane approximately parallel to a plane including the seat; the at least one return leg adjoins the top flange and extends downwardly therefrom towards the seat in a plane approximately parallel to a plane including the at least one back flange; the at least one back flange and the at least one top flange adjoin at a first junction and the at least one top flange and at least one return leg adjoin at a second junction to form a bracket for abutting an upper surface and two side surfaces of a support; and the at least one stiffening element adjoins the at least one back flange and the at least one top flange and extends over the first junction and/or adjoins the at least one return leg and the at least one top flange and extends over the second junction for resisting bending of the bracket formed by the at least one back flange, at least one top flange and at least one return leg.

19.A joist hanger substantially as hereinbefore described with reference to or as shown in the accompanying drawings.